SWT simple example

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.widgets.*;

public class App {
    public static void main(String[] args) {
        final Display display = new Display(); // for MacOS X add "-XstartOnFirstThread" to VM arguments
        final Shell shell = new Shell(display, SWT.SHELL_TRIM);
        final Label label = new Label(shell, SWT.NONE);
        label.setText("Hello world! Please click me!");
        label.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseDown(MouseEvent e) {
                final MessageBox messageBox = new MessageBox(shell);
                messageBox.setMessage("Message");
                messageBox.setText("Header");
                messageBox.open();
            }
        });

        label.pack();
        shell.pack();
        shell.open();

        while (!shell.isDisposed())
            if (!display.readAndDispatch())
                display.sleep();
        display.dispose();
    }
}